Bosch has been slow to put out applications for their Platinum +4
plugs, and seems to be doing a lot of testing. It took a long while
for Bosch to publish a part number for my Alfa GTV-6. I would
imagine that these plugs are best used in carefully metered (fuel
injected) engines with high energy ignition systems. If I were
Bosch, I would be sure they were good on emissions out to about
100,000 miles before marketing them.
I wonder if the relatively tiny center electrode on a platinum plug
might be more prone to fouling in a badly adjusted carburated engine
than a standard plug.
BTW---The +4 plugs are first cousins to an old Italian standby, the
Lodge plug. Similar design, no platinum, came in two heat ranges. I
was having trouble passing smog a few years ago and thought I'd try a
set of Lodges just for laughs. My Alfa mechanic swore by them in
Alfas for smog testing. Many Alfa drivers swear at them for fouling
or for having a short useful lives, but I suspect problems have to do
with poor oil control. In a tight fuel injected engine they lasted
me 12,000 mi+. In the B they caused the weirdest reading of the
electric tach, and didn't seem to do anything for idle quality, so I
put them back in the Alfa.
Chris
At 3:27 PM -0600 9/29/2000, Peter wrote:
> There is a newer plug marketed by Bosch called the Platinum +4.
>This has 4 ground electrodes. Bosch makes only 16 part numbers of these and
>they are aimed at consumers with late model cars. There are no LBC
>applications printed nor any car before 1983. Bosch claims that they are
>tested in every application, and only those that proved satisfactory (or
>that they bothered to try them in) are listed. This they claim assures them
>of customer satisfaction which seems to be the case. Some people have had
>great success putting them in LBCs, claiming increased performance, yadda,
>yadda, yadda. The applications are arrived at by finding a "current" car
>that uses the same stock plug as the desired LBC application and using the
>+4 equivalent. Bosch, of course, absolves themselves of any responsibility
>for such mis-application.
--
Chris Attias
Aptos, CA
'64 MGB
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